1. Field of the Invention
This invention relates to a method for the oxidation of oxidizeable components of a gas-borne stream, and more specifically to the treatment of cooking fumes to reduce the pollutants content thereof.
2. Description of the Related Art
Ongoing efforts to protect the environment from polluting by-products of commercial activities have led to concern regarding the release of particulate emissions from food cooking operations. The cooking of food generates large quantities of cooking fumes which include particulate emissions, such as droplets of grease and cooking oils, carbon monoxide and hydrocarbon-derived gases including reactive organic gases. If left untreated, these pollutants are released into the air. Conventional approaches to removing particulate pollutants from cooking fumes involve filtration of the fumes by water scrubbers or various types of filters. Filtration, however, is an expensive and inefficient method for abatement of particulate emissions, particularly in applications where the volume of particulate emissions is high.
As an alternative to filtration, some attempts have been made to catalytically convert the components of cooking fumes to less noxious species. For example, French Patent FR 2 663 241 discloses a method for treating air that has been contaminated by vapors released during deep fat frying of food, the method including passing the air through a mechanical filter, an electrostatic filter and an oxidation catalyst comprising platinum and alumina.
U.S. Pat. No. 4,138,220 discloses a method and apparatus for catalytically oxidizing grease, fats, oils and/or other hydrocarbons in fumes emanating from sources such as a cooking grill or the like. The disclosed apparatus may include a honeycomb structure having a platinum-containing catalyst material coated thereon.
U.S. Pat. No. 5,094,222 discloses a catalytic composite, and a food cooker containing such catalytic composite, for decomposing fats and oils by oxidation. A silicon oxide or aluminum oxide anodic oxidation film is formed on an air-permeable metal support and an oxidation catalyst is carried on the surface of the anodic oxidation film. The oxidation catalyst is selected from the group consisting of an oxide of one or more of manganese, iron, cobalt, nickel, copper, lanthanum and cerium.